SAN FRANCISCO — Uber confidentially filed paperwork on Thursday to go public, according to two people with knowledge of the matter, officially moving toward what is expected to be one of the biggest and most anticipated tech company stock market debuts ever.

The ride-hailing company filed its paperwork with the Securities and Exchange Commission on the same day that its rival Lyft also filed for an offering, said the people, who requested anonymity because they were not authorized to speak publicly. Each company is rushing to beat the other to the public markets in the first half of next year amid a fair climate for technology I.P.O.s and worries of a potential economic recession.

Uber and Lyft declined to comment. The Wall Street Journal reported earlier that Uber had filed its public offering documents.

Uber, the world’s biggest ride-hailing company, has been told by investment bankers that it could be worth as much as $120 billion in an I.P.O. At that valuation, it would be the biggest offering since the Alibaba Group of China began trading on the New York Stock Exchange in 2014. It would dwarf the market capitalization of more established companies such as Goldman Sachs, putting it at around the same value as I.B.M. or McDonald’s. And it would likely bring enormous windfalls for many of its investors, founders and employees.

Uber and Lyft are expected to presage a wave of I.P.O.s by other tech start-ups, many of which have delayed going public for years because of the plentiful availability of private capital. But as these companies mature and their early investors push to cash out their stakes, many are readying for their stock market debuts.

Airbnb, the online room rental company, is among those that have made little secret that they are also preparing to become public companies. Slack, a workplace collaboration software company valued at $7.1 billion, recently hired Goldman Sachs to lead its I.P.O., said a person with knowledge of the plans. Slack declined to comment about hiring Goldman, which was reported earlier by Reuters.

“It is like the graduation. The adolescents have become adults,” said Mamoon Hamid, a venture capitalist at Kleiner Perkins Caufield & Byers. “The longest bull run in history is now culminating with a whole slew of I.P.O.s.” He added, “Uber is in the same ballpark as Facebook and Google.”

Morgan Stanley and Goldman Sachs have submitted proposals to take Uber public. Lyft, which was last valued by private market investors at $15 billion, recently picked JPMorgan Chase to lead its I.P.O.

Yet Uber faces a huge hurdle as it aims to go public: It is deeply unprofitable. Uber said last month that it lost $1.07 billion in the third quarter. As a privately held company, Uber is not obligated to report its earnings, but it has made a habit of doing so.

Ride-hailing — where people hail rides through their smartphone and drivers with their own cars supply the rides — is an inherently expensive business because the company has to pay to recruit drivers, expand in new markets and beat back rivals.

Uber’s chief executive, Dara Khosrowshahi, has focused on paring back the unprofitable segments of the company’s business. He has sold off its operations in Russia and Southeast Asia, where it faced heavy competition from local rivals, while expanding into potential new businesses like food delivery and bike and scooter rentals.

Wall Street investors and others are still expected to snap up Uber’s stock because it is growing quickly in a consolidating stock market with fewer I.P.O.s. Uber’s executives have said it is profitable in cities where it has operated the longest, but chooses to burn money on increasing revenue faster.

“Revenue growth is significantly more important than worrying about the bottom line at this point,” said Barrett Daniels, a partner at Deloitte who advises on I.P.O.s.

Uber began as a ride-hailing service for upscale clientele in 2009, the pipe dream of Garrett Camp, an entrepreneur who eventually tapped a friend, Travis Kalanick, to run the company. They quickly pushed the service into numerous cities with little regard for local laws, causing tension with established taxi companies, lawmakers and regulators.

As competitors like Lyft appeared, both rushed to compete for smaller fares. The rivals have since spent billions of dollars on fare subsidies to attract people to their platforms.

Passengers loved Uber’s convenience and embraced it in cities such as San Francisco, New York and London. Uber now operates in more than 600 cities across 63 countries, providing more than 15 million trips a day.

Venture capitalists and other investors, seizing on Uber’s rapid growth, shoveled billions of dollars into the company to help it dominate. The company’s investors include the venture capital firm Benchmark, First Round Capital, TPG, SoftBank, Toyota and Fidelity Investments. Many of them are set to reap big returns from an I.P.O.

“Uber’s stock is widely distributed, and it will transform the lives of many thousands of families who have worked hard for this outcome,” said Matt Ocko, a venture capitalist who invested in Uber when it was a young company. Many Uber employees will go on to start other companies, he said. “This ‘virtuous cycle’ is still a big part of what makes the Valley great,” he added.

Over time, Uber branched out into different areas, like food and retail delivery, e-bike and scooter rentals, trucking and freight management and autonomous vehicles — even trying to build flying automobiles. Some of these efforts have run into difficulties, including earlier this year when an Uber driverless car killed a pedestrian in Tempe, Ariz.

Uber underwent a rocky 2017 when its workplace culture faced scrutiny for sexual harassment and for putting growth above all other considerations. Mr. Kalanick was ousted in June 2017 after shareholders staged a revolt against him.

Mr. Khosrowshahi was appointed Uber’s chief executive a few months later. He has vowed to improve the company’s culture and mend broken relationships with regulators, lawmakers and others.

Uber’s backers are eager to put last year’s troubles behind them. “I know Dara has the full trust of investors and employees, and we are confident he knows what he’s doing,” said Chris Sacca, an early investor in the company.

“We’re not done by any means, but if you look at where we were one year ago, we were dealing with fundamental issues of governance, of board alignment, of these continuing battles amongst power-brokers on our board and whether or not we were going to have SoftBank with us or against us,” Mr. Khosrowshahi said in an interview with The New York Times earlier this year. “Those were very important issues to deal with and to resolve, and I think we resolved them quite effectively in a positive way.”